Mark Wahlberg's Post-Training Guilty Pleasure: Cookies!

Mark Wahlberg put himself through a punishing workout regime and a strict diet for more than four years for his role in The Fighter. What did he eat when it was all over?

"Everything," the star, who plays champion boxer Micky Ward in the film, told PEOPLE at Friday night's Cinema Society premiere in New York City. "I just became obsessed with chocolate-chip cookies and stuff that I never really had any interest in eating [before]."

But his wife, Rhea Durham, had some issues with his post-film indulging.

"She said, 'You might as well take care of yourself,'" Wahlberg, 39, says. "But I needed a break from it. Certainly four-and-a-half years was very draining. I needed that time off, and now I need to get back in there."